So basically for a song I'm learning, I need to tune to Drop C. However, I recently had to buy a new tuner (I sort of smashed my other one in frustration. ). I'm a terrible ear tuner, and I cannot tune my G string down to F, because the tuner I have doesn't show the F note. This is probably a huge noob question, but how can I tune to F if my tuner only shows the notes, B, E, A, D, G and C?

Once again, I apologise if this is a noobish question, but I really need help!

Thank you.
You've probably never heard of it, but it's an Indie Guitar and Bass Tuner gt10. I got it for free because I'm friends with the guy who owns the Indie Guitar company, but it's really not that great...
is there a flat button?

go to G and down 2 flats (a whole step down)
Just call me Julius, J, etc.
Taking an Internet break for a while, will come on when I can.
Yeah that one.

All that happens is if you press sound, you cycle through what each string sounds like in standard tuning, with no additional symbols except for what string it is, if you press pitch it just goes up from 435 HZ to 445 HZ which doesn't effect anything, and if you press mode it changes to either Bass or Guitar setting.

But I was wondering, If I tune down from G I get E, so would Eb (two flats down, I think?) would that be the same as F? Or am I completely wrong?
You use one of the other strings at the appropriate fret to give you an F and tune to that. Just keep playing the two strings (one of which will be fretted obviously) till they sound the same.